Treatment of textile materials



Sepi 26, 1944. H. CORTEEN 2,359,036

TREATMENT OF TEXTILE MATERIAL I Filed Dec, 27, 1940 DIV/4 PatentedSept.26,' 1944 1 TREATMENT OF TEXTILE MATERIALS Harry Corteen,Manchester, England, assignor to Tootal Broadhurst Lee Company, Limited,Manchester, England, a British company Application December 27, 1940,Serial No. 371,881

In Great Britain February 1, 1940 6 Claims.

The present invention relates to the treatment of textile materials, andmore particularly to the production of a crease line therein.

It is desirable that articles such as pleated fabrics, collars, andcuifs'should have a permanent line or lines along which the fabricsreadily fold'so that the original creases can be easily reproduced, forexample by pressing or ironing during laundering.

It has previously' been proposed to form" a crease-line by varying thenumber of threads in or about the line or by differential application ofacid which may or may not be followed by pressure.

The present invention consists in a method of forming a fabric having atendency to fold along a predetermined line in which a viscous liquidcontaining a film-forming stiffening agent is applied to an area alongand including both sides of a desired crease-line, and then applyingmechanical pressure to the folded fabric first to the crease and then tothe remainder of the fabric to expel more of the stifieningagent fromthe crease-line than from the adjacent areas on either side. v

The stiffening agent is preferably applied by the use of a viscousliquid containing a polymerized material with or without a plasticisin'gagent. Thermosetting resins are especially valuable materials. Thestiffening agent may be applied to one face only of the fabric.

The linear gap of less stiffened material in the case of a collar. ispreferably less than 0.25 cm. and is usually between 0.10 and 0.17 cm.Although we may-treat the whole surface, we prefer to stiffen a localarea on either side of the crease-line the depth of which local area isless than half the height of the collar when folded and preferably lessthanl cm. e. g. about 1 cm.

A suitable amount of film-forming solid is such as will give to thetreated areasof the fabric a weft flexural rigidity at least twice andusually three to four times that of the weft of the less treated lineargap.

The film-forming solidmust besuch as produces a stiffening effect atnormal temperatures afterapplication to the cloth. .Suitable solidsincludesynthetic, polymers which are hard rather than rubber-like andwhich usually have a molecular weight greaterthan 50,000; for example,we 7 v include the use of highly polymerised vinyl acetate and mixturesof highly polymeris'ed vinyl fer, however, to use far-condensedthermo-setting condensing urea and formaldehyde in presence of acatalyst for a sufficiently long time. to form a non-crystallisablecolloid.

The film-forming solid, e. g., in the form of p a dispersion or solutionis applied to the part of the cloth where the fold is to be producedtogether with the adjacent areas, for example by spreading it on oneface of the cloth only, and subsequently to fold the textile fabric sothat the film'-forming material lies inside" the fold. .We then applypressure with or without heat preferably in a direction at right anglesto the crease; for example, by folding the fabric along the crease-lineand then either passing the creased fabric laterally through a mangle,crease first,

or hot ironing it crease first, in a direction at I right angles to thcrease-line, or squeezing it between hinged plates as hereinafterdescribed. Thisapplication of pressure helps to expel the majority ofthe forming material from the actual crease-line and is'assisted by thethickness of the folded cloth at this point. This effect is greatlyimproved by choosing a film-forming material of viscosity suitable tothe nature of. the cloth being treated. For example, when the viscosityis too great or the cloth too finely woven or the cloth contains a largeamount of a filler or wax the film-forming material does not pene-,trate the fabric and this tends to give a rough surface finish and whenthe viscosity of the filmforming material is too low or the cloth tooabsorbent little migration from the crease-line takes place and this isalso unsatisfactory; Liquids of suitable viscosity penetrate into thefabric but not through to the other face or into the fibres of thefabric; however, ancillary components of the film-forming material suchas plasticisers or solvents may do so. The stiffening agent may also beapplied as a solid with hot pressing.

We prefer to apply the film-forming material in the form of a liquidhaving a viscosity of not less than about 1400 c. g. s. units. In somecases the. viscosity of the liquid may be increased by the additionofammonium oleate or stearate but this tends to darken on being heated andthis is undesirable. We-prefer, therefore, to increase the viscosity ofthe liquid by other means, for example, by increasing the degree ofpolymerisation of the materials. In the case of urea-formalde-- hydecondensation products this may be done by adjusting the time allowed forcondensation in presence of a catalyst and using excess formaldehyde,preferably largely in the-form of paraform-' aldehyde to avoid excessivebulk. We have found resinous substances such as those produced by thatwhilst asis well-known the preliminary conperature to insolubilise thefilm-forming material after application to the cloth.

We have found that the final stiffness of the cloth can be varied byadding a plasticiser, in amount varying according to the degree ofstill!- ness required; this plastlciser by acting as a diluent controlsthe amount of urea formaldehyde resinous. material applied to the cloth.The presence of a suitable plasticiser also prevents the film-formingmaterial from accumulating on tween hinged iron plates, the foldedcollar beingplaced during pressing with the crease towards the hingesthus enabling pressure to be applied to the crease line of the collarmomentarily bee fore it is applied to the remainder of the collar. Inthis case. the plates are heated so that the squeezing and theinsolubilisation takes place in parts of the machine which is used forapplyin it to the fabric,

Where the film-forming solid is applied to the textile fabric fromsolution, for example, inan organic solvent such as toluene in the caseof polyvinyl acetate and polymethylmethacrylate mixtures, theapplication of the material should be followed by drying at atemperature sufiicient to evaporate the solvent.

It is preferred to apply the film-forming material to one face only. ofthe cloth and the cloth may be treated for example with a suitableamount of filler or wax to prevent undue penetration of the solidthrough to the other face.

The film-forming material may be applied tothe whole of the textilefabric especially where the invention is applied to the manufacture ofstiff or semi-stiff collars.

Titanium di-oxide or some other filler or colouring matter may be addedto the liquid..

The following is an example of the preparation of a suitable ureaformaldehyde condensation product and its application to the textilematerial.

Errample 60 8. of urea. is dissolved in 48 cc. of neutral 40% aqueousformaldehyde, 18 cc. of concentrated ammonia (sp. g. 0.88) added. Afterthe urea has dissolved 94.8 g. of paraformaldehyde is added. Themolecular ratio of urea to formaldehyde in this mixture is 123.8.

This mixture is then refluxed for 3 minute tartaric acid' and 60 cc. ofSextol (registered trade mark) phthalate, and this mixture is stableover a reasonable period of time and is suitable for application to thetextile material. Sextol'is a mixture ofthe three isomeric methylcyclohexanols'and the phthalate of Sextol is an emcient plasticiser forthe purpose of the present v invention. Moreover its viscosity is suchthat its addition does not substantially alter the visa singleoperation, whilst the collar is still folded. This does not lead tosticking between treated areas. Alternatively, if the plates are notheated. the insolubilisation is carried out as a separate heatingprocess. In the above example the amount of solid left on the cloth,after heating, was 17.6% calculated on the weight of cloth actuallytreated.

After treatment the collar has a permanent line along which it foldsreadily andthis effect is very fast to normal laundering processes. Witha typical '2-ply collar cloth a suitable amount ,of urea-formaldehydefilm-forming material to be applied to the cloth would be-between 10 and25 mgms. per square centimetre of cloth.

The invention maybe applied to textile materials other than wovenfabrics.

The invention includes the manufacture in this way of pleated or creasedfabrics and the treatment of collars and cuffs to obtain a crease-lineso that the pleats or crease-lines can be easily found and accuratelyironed. The invention is especially suitable for use in manufacturing acollar in which the rve in the plane of the collar is produced ac rdingto the method described in application No. 512,316.. In this case,

treatment according to the present process is carried out first so thatthe collar is creased before the production ofthe curve. Subsequentlywhen the curve has been produced and the collar laundered thecrease-line isin its correct curved form and the danger of losing thecurved creaseline through subsequent washing and ironing is avoided.

An embodiment of the invention is illustrated in the accompanyingdrawing in which- Figure l is a, plan view of a collar before folding,and Y Figure 2 is a. diagrammatic elevation, with parts in section,showing the treated collar folded over and being pressed down moretightly at the fold edge to displace the stiifening material therefromtoward theadiacent portions of the collar;

In'Figure l of the accompanying drawing I is the inner and 2 is theouter portion of a semistiii. collar. 3' is the linear less stiflenedarea forming the fold line and I and I are the more stiffened areas.

Figure-2 shows the treated and folded collar l and 2 having the lessstiil'ened fold line 8 and the more stiffened areas I and I beingpressed between the heated iron plates A and B hinged together at C sothat .when pressure 18 applied as indicated by the arrow, the-foldlineis subjmd to a greater pressure than the areas away from the foldline, whereby the stiffening material is partly discharged from the foldline toward the adjacent areas to provide the reduced stiffnessdescribed at the fold line. The plate A in the diagram is assumed to uand extended, for example at D, for increased stability.

I declare that what I claim is:

l. A method of forming a fabric having a natural tendency to fold alonga predetermined line which comprises applying a viscous liquidcontaining a film-forming stiffening agent to an area along andincluding both sides of a desired foldline applying mechanical pressureto the folded fabric to expel more of the stiffening agent from thecrease-line than from the adjacent areas on either side, and solidifyingthe stiffening agent on the fabric.

2. A method as claimed in claim 1 in which the stifiening agent isapplied to one face of the cloth only.

3. A method of forming a fabric having a tendency to fold along apredetermined line in which a film-forming stiffening agent is appliedto an area along and including both sides of a desired crease-line andthen mechanical pressure is applied to the folded fabric first to thecrease and then to the remainder of the fabric to expel more of thestiffening agent from the creaseline than from the adjacent areas oneither side.

4. A method of forming a collar having a natural tendency to fold alonga predetermined crease-line which includes the steps of applying awater-fast film-forming stiffening agent to part only of the inner faceonly of a collar blank in a local area containing the proposed foldline, folding the blank along said fold line so that the film-formingagent lies inside the fold, applying mechanical pressure to the foldedblank in such manner as to expel more of the stiffening agent from thefold line than from the adjacent areas on either side, and solidifyingthe stiffening agent on the blank.

5. A textile material having a pre-creased fold line containing a smallproportion of a deposit of water-fast film of solid stiffening agentbordered on each side thereof with a similar deposit in increasedproportion, whereby the textile material exercises a, tendency to foldrepeatedly along its pre-creased fold line.

6. A collar of textile fabric having a precreased fold line and bearinga water-fast film of stiffening agent on the inner surface of the fabricalong a local area near and including said fold line, said water-fastfilm of stiffening agent being present in a small proportion at the foldline and in larger proportions in the areas to pre-creased fold line.

HARRY CORTEEN.

